A method to rank heat sinks in practice: the heat sink performance tester

One way of cooling electronic devices is through enlarging the surface that is in contact with a fluid (usually air) by attaching a heat sink. Since literally thousands of heat sinks are available many designers are confronted with the question: which one? Very often the designer´s choice is based on cost and manufacturer´s data. Unfortunately, this data cannot be used with confidence because they are almost exclusively based on measurements in a closed duct, thereby disregarding bypass effects and inflow conditions. CFD modeling is no option unless time, a supercomputer and a calibration laboratory are available. This paper discusses a method to rank heat sinks given a certain application. The measurement is based on the extraction of the average heat transfer coefficient from time-dependent temperature curves as a function of velocity and bypass. Scaling the measured effective heat transfer coefficient by mass, volume, weight or height provides several performance metrics allowing designers a novel way of ranking heat sinks in conditions that resemble the application.